Abstract: Techniques which provide scalable techniques for managing multicast traffic in interconnected IP fabric data centers. More specifically, embodiments presented herein disclose an aggregated source technique used to address scalability issues for interconnected IP fabric data centers as well as disclose a secondary rendezvous point technique used to address backbone network (S, G) multicast state scalability. Additionally, embodiments disclosed herein include an approach for border leaf load balancing based on group destination addresses used by VTEPs.

Abstract: In one embodiment, a layer-2 network that includes a cloud switch is partitioned into a plurality of segments, each segment including one or more cloud switch domains that are coupled via a logical port to a corresponding one of a plurality of internal logical shared media links. One of the internal logical shared media links is provisioned as a hub. One or more remaining internal logical shared media links are defaulted to be spokes. A spanning tree protocol (STP) is executed within each segment. The logical port of each cloud switch domain advertises a pseudo root bridge identifier (ID) to cause the internal logical shared media link to appear attached to a Root. The advertised pseudo root bridge ID of the hub is chosen to have a higher priority than the pseudo root bridge ID of the spokes to establish a hub and spoke relationship among the segments.

Abstract: In one embodiment, a copy of an original packet of a traffic flow is created at an ingress leaf node of a cloud switch. The ingress leaf node forwards the original packet along a less-specific path through the cloud switch, the less-specific path based on a domain index of an egress domain for the original packet. The copy of the original packet is modified to create a more specific path learn request packet. The ingress leaf node forwards the more specific path learn request packet along the less-specific path through the cloud switch. The ingress leaf node received back a more specific path learn request reply packet that includes an indication of a fabric system port. The ingress leaf node then programs a forwarding table based on the indication of the fabric system port, to have subsequent packets of the traffic flow forwarded along a more-specific path.

Abstract: A segment within a virtual network is identified as being supported by a segment bundling device. The segment within the virtual network supports a first host connected to a first bridging device and a second host connected to a second bridging device. The segment bundling device is used to receive virtual network address information describing the virtual network segmentation identifier (ID) for the segment used for receiving virtual network traffic for the first and second host. A segment bundling table associating a bundle ID with the virtual network segmentation identifier based on the upper ID and the lower ID of the virtual network ID is generated by the segment bundling device. The segment bundling device is used to distribute the segment bundling table to traffic forwarding devices in the virtual network that interface with the first bridging device and the second bridging device.

Abstract: In one embodiment, a plurality of leaf switches that include host facing ports are configured as a cloud switch. An indication of connectivity between the leaf switches of the cloud switch and routing bridges (RBridges) external to the cloud switch may be added to link state packets (LSPs) sent over the at least one logical shared media link. A lookup table may be generated that specifies next hop leaf switches. The generated lookup table may be used to forward frames to one or more particular nexthop leaf switches. Further, traffic engineering parameters may be collected. Equal cost multipath (ECMP) nexthop leaf switches and distribution trees to reach one or more destinations may be examined. Traffic may be distributed across ones of them based on the traffic engineering parameters.

Abstract: In one embodiment, a first number of multiple spanning tree instances (MSTIs) are defined within a network. A second number of network segments associated with segmentation identifier (IDs) are also configured, where the first number of MSTIs is less than the second number of segmentation IDs. Segmentation ID to MSTI mappings are maintained that map each defined segmentation ID of the second number of network segments to one of the first number of MSTIs. A segmentation mapping digest is computed of the segmentation ID to MSTI mappings. Multiple spanning tree (MST) bridge protocol data units (BPDUs) are broadcast that include the digest of the segmentation ID to MSTI mappings.

Abstract: In one embodiment, a plurality of leaf switches that include host facing ports are configured as a cloud switch. An indication of connectivity between the leaf switches of the cloud switch and routing bridges (RBridges) external to the cloud switch may be added to link state packets (LSPs) sent over the at least one logical shared media link. A lookup table may be generated that specifies next hop leaf switches. The generated lookup table may be used to forward frames to one or more particular nexthop leaf switches. Further, traffic engineering parameters may be collected. Equal cost multipath (ECMP) nexthop leaf switches and distribution trees to reach one or more destinations may be examined. Traffic may be distributed across ones of them based on the traffic engineering parameters.

Abstract: An example method includes storing a portion of virtual PortChannel (vPC) information in a TRansparent Interconnect of Lots of Links network environment, deriving, from the portion of vPC information, a physical nickname of an edge switch to which a frame can be forwarded, and rewriting an egress nickname in a TRILL header of the frame with the physical nickname. In example embodiments, the vPC information can include respective vPC virtual nicknames, EtherChannel hash algorithms, hash values, and physical nicknames of edge switches associated with vPCs in the network environment. In some embodiments, the portion of vPC information can be derived from an Interested vPC Type Length Value (TLV) information of an Intermediate System to Intermediate System (IS-IS) routing protocol data unit (PDU).

Abstract: In one embodiment, a period between periodic transmissions of protocol data units (PDUs) used to form or maintain a link aggregation group is initially set to a fixed value. When a stress condition is detected, the period between periodic transmissions of PDUs is increased from the initial value. When the stress condition is determined to have eased, the period between periodic transmissions of PDUs is reduced back toward the fixed value.

Abstract: In one embodiment, one or more indicia of stress are monitored. Based on the one or more indicia of stress, it is determined a stress condition exists. In response to the stress condition, one or more link aggregation actors and partners are caused to enter a grace state for a grace period. While the one or more link aggregation actors and partners are in the grace state, link aggregation formation is paced on a plurality of links by delaying formation of one or more new link aggregation groups on the plurality of links until a hold is released. Upon expiration of the grace period, the grace state is exited.

Abstract: Synchronization of traffic multiplexing in link aggregation is described. In an embodiment, a first link aggregator and a second link aggregator are associated with a plurality of links. The first link aggregator maintains an identifier for each link indicating at least a state of enabled or disabled. A synchronized clock is established between the first link aggregator and the second link aggregator. A particular link of the plurality of links is transitioned. Wherein, the transitioning is performed by the first link aggregator sending, to the second link aggregator, a first message identifying a particular time to transition the particular link. The first link aggregator receives, from the second link aggregator, a second message indicating that the particular time is acceptable. In response to a determination that the second message indicates that the particular time is acceptable and that the synchronized clock has reached the particular time, transitioning the link.

Abstract: In one embodiment, a layer-2 network that includes a cloud switch is partitioned into a plurality of segments, each segment including one or more cloud switch domains that are coupled via a logical port to a corresponding one of a plurality of internal logical shared media links. One of the internal logical shared media links is provisioned as a hub. One or more remaining internal logical shared media links are defaulted to be spokes. A spanning tree protocol (STP) is executed within each segment. The logical port of each cloud switch domain advertises a pseudo root bridge identifier (ID) to cause the internal logical shared media link to appear attached to a Root. The advertised pseudo root bridge ID of the hub is chosen to have a higher priority than the pseudo root bridge ID of the spokes to establish a hub and spoke relationship among the segments.

Abstract: A method for image processing. The method comprises the steps of providing a touch panel, displaying an image on the touch panel, obtaining a dragging path generated by a user touching and dragging from a first to a second point on a surface of the touch panel, determining a rotation angle according to a relative position between the first and second points on the surface of the touch panel, and displaying the image rotated with the rotation angle on the touch panel.